The present invention relates to an apparatus and method for producing an exhaust processor configured to treat emissions from combustion product produced by an engine and particularly to an apparatus and method for assembling exhaust processor components. More particularly, the present invention relates to an apparatus and method for measuring and adjusting a gap between an exhaust processor substrate or filter and an exhaust processor case around the substrate.
For environmental reasons, engine combustion product or exhaust must be cleaned on board a vehicle before it is expelled into the atmosphere. This processing is accomplished by passing the untreated combustion product produced by the engine through an exhaust processor to minimize unwanted emissions.
Many exhaust processors include catalytic convertors that are used to filter contaminants from hot combustion product discharged from an engine exhaust manifold. Within a catalyzed exhaust processor, the combustion product is treated by a catalyzed ceramic or metal substrate or converter which converts the exhaust gases discharged from the engine primarily into carbon dioxide, nitrogen, and water vapor. The catalytic converter treats engine combustion product to produce an exhaust stream meeting stringent state and federal environmental regulations and emission standards.
After processing, the treated combustion product is then routed to a muffler to attenuate the noise associated with the combustion. It is also known to provide exhaust processors that include substrates that function as particulate traps to filter contaminant particulates without using a catalyst.
An exhaust processor typically includes a substrate encased within a metal sheet. The size and contour of the exhaust processors depends, in large part, on the space available for the exhaust processor in the vehicle exhaust system on the underside of the vehicle. Exhaust processors are well known as shown, for example, in U.S. Pat. No. 5,829,132 to Sickels et al; U.S. Pat. No. 5,293,743 to Usleman et al.; U.S. Pat. No. 5,118,476 to Dryer et al.; U.S. Pat. No. 4,160,010 to Ottle; U.S. Pat. No. 3,984,207 to Abthoff et al.; and U.S. Pat. No. 3,972,687 to Frietzsche, German Patent No. 3 430 398, and International (PCT) Application Publication No. WO 99/14119, entitled xe2x80x9cApparatus and Method for Encasing an Object in a Casexe2x80x9d and published on Mar. 25, 1999, the disclosures of which are incorporated by reference herein.
The present invention provides an apparatus for producing an exhaust processor comprising: a clamping device for applying a predetermined clamping pressure to clamp a first component of the exhaust processor about a second component of the exhaust processor to define a gap between the first component and the second component; a measuring device for measuring a size of the gap during application of the predetermined clamping pressure, the measuring device including a clamping pressure control system for adjusting the predetermined clamping pressure of the clamping device in response to the gap measurement so that the gap size is within a predetermined range; and a welder for welding a portion of the first component to an other portion of the first component when the gap size is within the predetermined range. The first component desirably is a case or other component of the exhaust processor and the second component desirably is a substrate or other component of the exhaust processor. A substrate mat or the like desirably is wrapped around the substrate and substantially fills the gap.
In a preferred embodiment, the measuring device also includes a camera for measuring the gap size. Desirably, the measuring device measures the size of the gap by taking gap measurements at a plurality of predetermined locations about the second component and averages these measurements to obtain the gap size. The control system preferably signals the clamping device to adjust the clamping pressure if the size of the gap measured by the measuring device is outside the predetermined range. The welder, if desired, may be a plasma welder.
The present invention also provides a method for producing an exhaust processor comprising the steps of: (a) applying a predetermined clamping pressure with a clamping device to clamp a first component of the exhaust component about a second component of the exhaust processor to define a gap between the first component and the second component; (b) measuring a size of the gap with a measuring device having a clamping pressure control system for adjusting the predetermined clamping pressure; (c) adjusting the clamping pressure with the clamping pressure control system if the size of the gap is outside a predetermined range; and (d) welding a portion of the first component to an other portion of the first component with a welder when the gap size is within the predetermined range. Desirably, steps (b) and (c) occur during step (a). In a preferred embodiment, the measuring device measures the size of the gap with a camera. The measuring device may make gap measurements at a plurality of predetermined locations about the second component and, if desired, average the gap measurements to determine the gap size. In a preferred embodiment, during step (d) the welder generates plasma for welding the portion of the first component to the other portion of the first component.
Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of referred embodiments exemplifying the best mode of carrying out the invention as presently perceived.